Microwave oven food-stirrer

ABSTRACT

A retrospectively-fitted multi-configurable microwave oven accessory the purpose of which is to provide an automated stirring capability of foodstuffs by use of the internal rotary plate of a microwave oven to provide a relative motion of the foodstuff and which is configured from a roof rail, a series of roof fittings and a series of stirring implements and where necessary may employ a food receptacle securing method. The device is shown at FIG.  7  of the attached drawings.

This invention relates to a retrospectively-fitted accessory tomicrowave ovens for use as a food-stirring device (hereafter referred toas a Microwave Oven Food-Stirrer).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is filed with the USPTO via the designation of the USAfor entry into the National Phase for PCT International ApplicationNumber PCT/GB01/05553.

PCT/GB01105553 was filed with WIPO on 13 Dec. 2001 and claims thepriority date of a National Application filed in Great Britain(Application Number GB0031231.4) on 21 Dec. 2000.

PCT/GB01/05553 has also designated Europe as a Region for the applianceof the PCT. The European Patent Office has given EPO Application Number01271787.2 to this application.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable.

BACKGROUND OF THE INVENTION REFERENCES

-   A. GB 2159027A (Thom EMI) dated Jun. 15, 1984.-   B. EP0312373 A (Raytheon) dated Oct. 14, 1988.-   C. GB 2230409 (Burton) dated Mar. 29, 1989.-   D. U.S. Pat. No. 5,151,569A (Samsung Electronics Co Ltd) dated May    21, 1991.-   E. WO 9310648 A (Jannaway) dated Nov. 16, 1992.-   F. GB 2300095A (Yinn Haur Co Ltd) dated Apr. 5, 1995.-   G. GB 2322271 A (Jones) dated Feb. 15, 1997.-   H. U.S. Pat. No. 4,751,357 (Boulard) dated Sep. 25, 1986.

It has been known for some time that the distribution of energy within amicrowave oven is not uniform and thus the even distribution of heatthrough food stuffs being cooked in a microwave oven is difficult toachieve. The development of a rotary plate as part of the internalfeatures of the cavity of a microwave oven went some way to overcomingthe inconveniences caused by this and the referenced prior art indicatesthat a device for permitting the practical stirring of food stuffsduring the cooking or reheating of them in a microwave oven has been anaspiration for some time. However, through the limited success of arotary plate in achieving a uniform heat distribution and thecomplexities and impracticalities of previous food stirring deviceideas, it is still a fact today that while cooking or re-heating eitherhigh or low viscosity foods (ie, stews, rice puddings, sauces, soupsetc) or beverages in a microwave oven, there is a need to interrupt thecooking process periodically in order to stir the food so as to ensurean even distribution of heat through it.

The idea of a Microwave Oven Food-Stirrer was born from the need formechanism to permit stirring of food stuffs during the cooking orreheating of them in a microwave oven so as to achieve a far more evendistribution of energy throughout the food and allow the cooking periodto be continuous (a procedure recommended for best results in manydishes). Furthermore, the mechanism to meet this purpose would need tobe uncomplicated in design, be, as a manufactured product, compatiblefor use with any size of domestic microwave oven having a rotary plateas part of its internal features, compatible for use with an extremelywide range of food/beverage receptacles including those that are narrow,easy for a layman to operate and clean, provide insignificantobstruction to the placement of items within the microwave oven cavityboth when in use and when not in use and be able to be retrospectivelyfitted by a layman to an existing microwave oven. A Microwave OvenFood-Stirrer is a device to facilitate this function.

While prior art at References A to H has attempted to meet thefunctionality offered by the Microwave Oven Food-Stirrer, it has failedthrough the complexities and/or inadequacies of its design making itimpractical for use in a microwave oven for one or more of the followingreasons:

-   -   a. The operation of it, in particular preparation for use,        hampering the overall cooking process.    -   b. The obstruction caused by it to placement of additional items        (primarily a receptacle) within the oven cavity.    -   c. The fact that it may be used with a very limited design of        receptacle only; in particular, it is incompatible with the use        of tall, narrow receptacles (jugs, beakers etc).    -   d. Inconvenience in its operation due to its non-ergonomic        characteristics.

For example:

-   -   a. The device at Reference B makes use of either a “horizontal        bar removably engaging opposing walls of the microwave oven”, or        a horizontal arm supported by other means protruding into the        oven cavity to support a vertical shaft. Although the method for        attaching the vertical shaft to a horizontal bar/arm allows for        both adjustment of the vertical position of the shaft to meet        the optimum stirring capability and security of the shaft's        vertical position during operation, the shaft must be located in        the attachment before a receptacle is placed into the oven        cavity. While the attaching method allows for vertical movement        of the shaft, the vertical movement is limited and therefore the        shaft together with the presence of the horizontal bar/arm cause        significant obstruction to the placement of receptacles within        the oven cavity, in practice allowing for the placement within        the oven cavity of limited designs of receptacle only.        Furthermore, the items comprising the device require potentially        more than a simple single movement action to fix them in place.    -   b. The device at Reference E makes use of either a sprung frame        or, when “supplied as original equipment with a microwave oven”,        a fitment to the oven roof. In either case, the stirring        implement of the device is attached via a swinging holder        allowing for the stirring implement to be inserted, either        before, during or after a receptacle is in place, in a        horizontal orientation and rotated to the vertical into a        receptacle containing a food/beverage. The design of the prior        art does not allow for security of the shaft's vertical position        during operation. Use of a frame restricts placement of        receptacles within the oven cavity and the requirement for        rotation of the device further restricts use of receptacles to        only those which enable the rotation ie those with a rim        diameter not significantly less than the length of the stirring        implement. In particular therefore, the prior art is rendered        impracticable for use with tall, narrow receptacles such as jugs        and beakers.    -   c. Much of the prior art does not lend itself to easy cleaning        whereas the Microwave Oven Food-Stirrer has been designed such        that its external surfaces, particularly those of its permanent        fittings are easily accessible.    -   d. Much of the prior art is located within an oven cavity via a        device which bridges, utilises or runs perpendicular to the side        walls of the cavity and none of the prior art readily        facilitates the adjustment of a stirring device transversely        through a receptacle. Where transverse adjustment is permitted,        it is in a direction perpendicular to the side walls of the        cavity only as opposed to a direction perpendicular to the rear        wall of the cavity. Location and subsequent variation of the        positioning of a stirring device in a direction perpendicular to        the rear wall of the cavity accords with the direction in which        receptacles are placed into and removed from the oven, thus        facilitating greater ergonomics in the fitment and adjustment        process.

While primarily this invention is intended to be a separate stand-aloneenhancement able to be fitted retrospectively by a layman to anymicrowave oven which has a rotary plate as part of its internalfeatures, it could be part-incorporated as an integral design feature ofan oven during oven manufacture to provide for either the intendedstirring accessory described as the main feature of the invention, or,with further modification to both the invention and a microwave oven,one which is rotated about a vertical axis through an oven roof.

BRIEF SUMMARY OF THE INVENTION

The main feature of the invention is a multi-configurable microwave ovenaccessory comprising no moving mechanical or electrical parts, thepurpose of which is to provide an automated stirring capability foreither high or low viscosity foods or beverages held in a receptacle inany size of domestic microwave oven and which:

-   -   a. Makes use of the internal rotary plate of a microwave oven to        provide a relative motion of a food/beverage.    -   b. In a singularly configured form comprises:        -   (1) A Roof-Rail.        -   (2) A Roof-Fitting.        -   (3) A Stirring Implement.    -   c. Is configured from:        -   (1) A single Roof-Rail being an ‘I’ sectioned strip having            an insignificant effect on the reduction of the volumetric            capacity of the oven cavity and not obstructing the            placement of items within, which is secured to the ceiling            of the microwave oven cavity with adhesive as a permanent            fitting along the radial running perpendicular to the back            wall of the oven, from the back wall to just beyond the            centre thus providing for the ergonomic fitting to it and            subsequent adjustment of a Roof-Fitting.        -   (2) A series of Roof-Fittings designed to ride snugly along            the Roof-Rail such that they may be positioned either            singularly or in tandem at any point on the rail, except            that occupied by another Roof-Fitting, to provide for the            optimum stirring capability, varying in length so as to            provide for a variation in length of a full configuration of            the device along its longitudinal axis and which incorporate            a female ‘bayonet’ type fitting positioned to be facing the            front of the oven so as to facilitate easily the attachment            of a Stirring Implement.        -   (3) A series of Stirring Implements varying in design so as            to provide for a variation in stirring function of a full            configuration of the device and having a male ‘bayonet’ type            fitting incorporated into their design for attachment to            Roof Fittings positioned so that on insertion to the female            bayonet fitting of the Roof-Fitting, the Stirring Implement            is angled to provide the optimum stirring capability within            a food/beverage held in a receptacle.

Optional features, the purpose of which is to ensure more fully therelative motion of a food/beverage to the main feature while the latteris in use, are:

-   -   a. A non-slip mat to be placed between the receptacle and the        oven rotary plate.    -   b. A Secure Bowl and Rotary Plate assembly, consisting of a        studded bowl and a complementing slotted rotary plate. (A Secure        Bowl and Rotary Plate assembly would require specific sizing to        fit a particular oven and would substitute the original rotary        plate fitted to the oven and, for its intended purpose, any        receptacle placed within).

All constituent parts of the invention would need to be manufactured ina microwave-proof material.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The invention is further described by reference to the accompanyingdrawings in which:

a. FIG. 1 shows the separate elements of a single configuration of themain feature of the invention.

b. FIG. 2 shows front and side views of a Roof Fitting attached to theRoof Rail.

c. FIG. 3 shows a single configuration of the main feature of theinvention dispersing heat through a food/beverage held in a receptacleplaced on a microwave oven rotary plate.

d. FIG. 4 shows some of the numerous Stirring Implement design options.

e. FIG. 5 shows further Stirring Implement design options.

f. FIG. 6 shows the optional Rotary Plate and Bowl assembly feature.

g. FIG. 7 shows a single configuration of the main feature of theinvention in situ with the optional Rotary Plate and Bowl assembly.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, a single configuration of the main feature ofthe invention comprises:

-   -   a. The Roof-Rail (1) being an ‘I’ sectioned strip having an        insignificant effect on the reduction of the volumetric capacity        of the oven cavity and not obstructing the placement of items        within, which is secured to the ceiling (14) of the microwave        oven cavity with adhesive as a permanent fitting along the        radial running perpendicular to the back wall of the oven, from        the back wall to just beyond the centre thus providing for the        ergonomic fitting to it and subsequent adjustment of a        Roof-Fitting (2).    -   b. A Roof-Fitting (2) designed to ride snugly along the        Roof-Rail (1) such that it may be positioned to provide for the        optimum stirring capability, selected to provide the desired        depth of the invention into the food/beverage to be stirred and        which incorporates a female ‘bayonet’ type fitting positioned to        be facing the front of the oven so as to facilitate easily the        attachment of a Stirring Implement (3).    -   c. A Stirring Implement (3) selected to provide the desired        stirring function. (Stirring Implements (3) are designed for        different mixing/stirring functions and different sized        receptacles/bowls. Generally, they are contoured to the walls of        different receptacle types in order to provide optimum stirring        capability and bring the hotter food toward the centre—see        FIG. 3. Of the numerous Stirring Implement design options, some        are a ‘Whisk-type’ (FIG. 4, Item 6), ‘Fork-type’ (FIG. 4, Item        7), ‘Wave-type’ (FIG. 4, Item 8), and ‘Concave-type’ implements        (FIG. 4, Item 9). More complex ‘aerodynamic’ type designs, such        as those shown in FIG. 5, Items 10 and 11, are other options for        achieving a more even distribution of heat through the        food/beverage).

In operation, with the permanent Roof-Rail (1) in place, a singleconfiguration of the invention is positioned to carry out its functionby either of the 2 following methods:

-   -   a. First attaching a Stirring Implement (3) to a Roof-Fitting        (2) and engaging the Stirring Implement (3) and Roof-Fitting (2)        securely, thence placing the connected Roof-Fitting (2) and        Stirring Implement (3) into a receptacle (4) containing the        food/beverage to be stirred, thence placing the receptacle (4)        containing the connected Roof-Fitting (2) and Stirring Implement        (3) into the oven cavity, thence attaching the connected        Roof-Fitting (2) and Stirring Implement (3) to the Roof-Rail (1)        via the Roof-Fitting (2), thence positioning the Roof-Fitting        (2), with Stirring Implement (3) attached, along the Roof-Rail        (1) so as to provide for the optimum stirring capability of the        food/beverage in its receptacle (4).    -   b. First attaching a Roof-Fitting (2) to the Roof-Rail (1), then        placing a Stirring Implement (3) into a receptacle (4)        containing the food/beverage to be stirred, thence placing the        receptacle (4) containing the Stirring Implement (3) into the        oven cavity, thence offering the Stirring Implement (3) to the        roof-fitting (2) and engaging the Stirring Implement (3) and        Roof-Fitting (2) securely, thence positioning the Roof-Fitting        (2), with Stirring Implement (3) attached, along the Roof-Rail        so as to provide for the optimum stirring capability of the        food/beverage in its receptacle (4).

The receptacle (4) which may be used during operation of the MicrowaveOven Food-Stirrer is limited in its size and design only by thedimensions of the microwave oven cavity and the fact that its rim mustpass under the Roof-Rail (1) and allow sufficient space for fitment ofthe Roof-Fitting (2) to the Roof-Rail (1) ie, a receptacle (4) may benot greater in height than the distance from the rotary plate (5) onwhich its sits to just under the ‘I’ sectioned Roof-Rail (1), this beingpotentially a little over finger-width from the ceiling (14) of the ovencavity. This is a significant advantage of the Microwave Oven FoodStirrer over the prior art.

A configuration is denied both movement along and about its longitudinal(vertical) axis, excepting that required to connect and disconnect itsconstituent parts, and pivotal movement about a horizontal axis.

In operating the microwave oven, the rotary plate (5) will provide amotion of the food/beverage within the receptacle (4) relative to theStirring Implement (3), thus providing for the stirring function of thedevice and the enhanced dissipation of heat through the food/beverage.

On completion of the cooking period, a single configuration of theinvention is removed from the oven by either of the 2 following methods:

-   -   a. First decoupling the connected Roof-Fitting (2) and Stirring        Implement (3) from the Roof-Rail (1) such that the connected        Roof-Fitting (2) and Stirring Implement (3) is retained in the        receptacle (4), thence removing the receptacle (4) from the oven        cavity, thence removing the connected Roof-Fitting (2) and        Stirring Implement (3) from the receptacle (4), thence        decoupling the Roof-Fitting (2) from the Stirring Implement (3).    -   b. First decoupling the Stirring Implement (3) from the        Roof-Fitting (2) such that the Stirring Implement (3) is        retained in the receptacle (4), thence removing the receptacle        (4) from the oven cavity, thence removing the Stirring Implement        (3) from the receptacle (4), thence removing the Roof-Fitting        (2) from the Roof-Rail (1).

To facilitate a greater capability for stirring a food/beverage, eitheridentical or differing configurations of the connected Roof-Fitting (2)and Stirring Implement (3) may be attached to the Roof-Rail (1) so as tofunction simultaneously throughout an operating period of the microwaveoven.

Should the viscosity of the food/beverage be judged to impair or denythe relative motion of the Stirring Implement (3) to it, throughslippage of the chosen receptacle (4) on the rotary plate (5), either ofthe following optional features of the invention may be employed toensure a relative motion is maintained:

-   -   a. A non-slip mat to be placed between the food receptacle and        rotary plate.    -   b. A Secure Bowl and Rotary Plate assembly, consisting of a        studded bowl (12) and a complementing slotted rotary plate (13).

While the invention is intended to be a separate stand-alone enhancementable to be fitted retrospectively by a layman to any microwave ovenwhich has a rotary plate as part of its internal features, to furtherenhance the stirring capability of the invention in a specific microwaveoven, both the invention, and the microwave oven may be modified furtherto allow for:

-   -   a. A variable-speed Rotary Plate. (Designing the rotary plate        turning mechanism so that the rotary plate could rotate at        various speeds would permit varying speeds of stirring action.        Different speeds may be optimised for different food/beverage        types).    -   b. Secondary rotation of the Stirring Implement. (To enhance the        stirring/whisking effect, the Microwave Oven Food Stirrer, as an        integral part of a microwave oven, could be designed to rotate        through its ‘point of contact’ with the oven roof. In this case,        the Roof-Rail (I) would not feature as part of the item).

SEQUENCE LISTING

Not Applicable.

1. A microwave oven comprising a microwave oven cavity having a ceiling,means for energizing said oven cavity with microwave energy; areceptacle for holding food, a rotary plate for rotating said receptacleplaced thereon within said oven cavity; an apparatus for stirring foodin the receptacle while heating with microwave energy, the food stirringapparatus being formed of a microwave compatible material and beingconfigured from a roof-rail, a series roof fittings and a series ofstirring implements; said roof-rail being an I-sectioned strip, which issecured to the ceiling of the microwave oven cavity with adhesive as apermanent fitting along the radial running perpendicular to the backwall of the oven cavity; the series of roof-fittings designed to ridesnugly along the roof-rail and such that one or more may be positionedat any point on the rail to provide for the optimum food stirringcapability, varying in length so as to provide for a variation in lengthof a full configuration of the apparatus along its longitudinal axis andincluding a female bayonet-type fitting positioned to be facing thefront of the oven cavity so as to facilitate easy attachment of thestirring implement; the series of stirring implements varying in designso as to provide for a variation in stirring function of a fullconfiguration of the apparatus and having a male bayonet-type fittingfor attachment with the female bayonet fitting of the roof fitting andwhich is positioned such that when inserted into the female bayonetfitting of the roof fitting, the stirring implement is aligned withinthe food in the receptacle so as to provide for the optimum stirringcapability of the apparatus.
 2. A microwave oven as claimed in claim 1and for which the receptacle which may be used during operation islimited in its size and design only by the dimensions of the microwaveoven cavity and the fact that its rim must pass under the roof-rail andallow sufficient space for fitment of the roof-fitting to the roof-rail.3. A microwave oven as claimed in claim 2 and for which the foodstirring apparatus is denied both movement along and about itslongitudinal (vertical) axis, excepting that required to connect anddisconnect its constituent parts, and pivotal movement about ahorizontal axis.
 4. A microwave oven as claimed in claim 3 and for whichthe food stirring apparatus, by virtue of it design, is supported intotal through its contact with the ceiling of the microwave oven cavityand is therefore not reliant on support directly or otherwise fromeither, the oven floor or walls, or the receptacle containing the food.5. A microwave oven as claimed in claim 4 and for which access toexternal surfaces of the food stirring apparatus for cleaning of boththe removable parts and those retained in the oven cavity after use isdirect and easy.
 6. A microwave oven as claimed in claim 5 and for whichthe stirring Implements of the food stirring apparatus are designed tooptimize different stirring functions and are generally contoured to thewalls of different receptacle types in order to bring the hotter foodtoward the centre and which have amongst their designs, ‘wave-type’,‘whisk-type’, ‘fork-type’, ‘concave-type’ and ‘aerodynamic-type’.
 7. Amicrowave oven as claimed in claim 6 and for which the food stirringapparatus could be part-incorporated as an integral design feature of anoven during oven manufacture to provide for either the intendedstationary stirring accessory, one which is rotated about a verticalaxis through an oven roof and/or one for which the stirring capabilitymay be varied by providing for a variable-speed rotary plate.
 8. Amicrowave oven as claimed in claim 7 wherein a non-slip mat is placedbetween the receptacle and the rotary plate to ensure more fully therelative motion of a food/beverage to the stirring apparatus.
 9. Amicrowave oven as claimed in claim 8 wherein a studded bowl andcomplementary slotted rotary plate are provided to ensure more fully therelative motion of a food/beverage to the stirring apparatus.
 10. Foruse in a microwave oven comprising a microwave oven cavity having aceiling, means for energizing said oven cavity with microwave energy; areceptacle for holding food, a rotary plate for rotating said receptacleplaced thereon within said oven cavity; a multi-configurable accessoryfor stirring the food in the receptacle while heating with microwaveenergy comprising a single roof-rail, a series of roof fittings and aseries of stirring implements, all being formed of a microwavecompatible material; said single roof-rail being an I-sectioned strip tobe secured to the ceiling of the microwave cavity with adhesive as apermanent fitting along the radial running from just forward of thecenter point of the ceiling to the back wall of the oven cavity andmeeting the latter at a perpendicular; the series of roof-fittingsdesigned to ride snugly along the roof-rail and such that one or moremay be positioned at any point on the rail to provide for the optimumfood stirring capability, varying in length so as to provide for avariation in length of a full configuration of the accessory along itslongitudinal axis and including a female bayonet-type fitting positionedto be facing the front of the oven cavity so as to facilitate easyattachment of the stirring implement; the series of stirring implementsvarying in design so as to provide for a variation in stirring functionof a full configuration of the accessory and having a male bayonet-typefitting for attachment with the female bayonet fitting of the rooffitting and which is positioned such that when inserted into the femalebayonet fitting of the roof fitting, the stirring implement is alignedwithin the food in the receptacle so as to provide for the optimumstirring capability of the accessory.
 11. A multi-configurable microwaveoven accessory as claimed in claim 10 and for which the receptacle whichmay be used during operation is limited in its size and design only bythe dimensions of the microwave oven cavity and the fact that its rimmust pass under the roof-rail and allow sufficient space for fitment ofthe roof-fitting to the roof-rail.
 12. A multi-configurable microwaveoven accessory as claimed in claim 11 and for which a singleconfiguration is denied both movement along and about its longitudinal(vertical) axis, excepting that required to connect and disconnect itsconstituent parts, and pivotal movement about a horizontal axis.
 13. Amulti-configurable microwave oven accessory as claimed in claim 12 andwhich by virtue of it design, is supported in total through its contactwith the ceiling of a microwave oven and is therefore not reliant onsupport directly or otherwise from either, the oven floor or walls, orthe receptacle containing the food.
 14. A multi-configurable microwaveoven accessory as claimed in claim 13 and for which access to externalsurfaces for cleaning of both the removable parts and those retained inthe oven cavity after use is direct and easy.
 15. A multi-configurablemicrowave oven accessory as claimed in claim 14 and for which theStirring Implements are designed to optimize different stirringfunctions and are generally contoured to the walls of differentreceptacle types in order to bring the hotter food toward the centre andwhich has amongst its stirring Implement designs, ‘wave-type’,‘whisk-type’, ‘fork-type’, ‘concave-type’ and ‘aerodynamic-type’.
 16. Amulti-configurable microwave oven accessory as claimed in claim 15wherein a non-slip mat is placed between the receptacle and the rotaryplate to ensure more fully the relative motion of a food/beverage to thestirring apparatus.
 17. A multi-configurable microwave oven accessory asclaimed in claim 16 wherein a studded bowl and complementary slottedrotary plate are provided to ensure more fully the relative motion of afood/beverage to the stirring apparatus.